Personal computers and laptop computers are increasingly being used as devices for sound capture in a variety of recording and communication scenarios. Some of these scenarios includes recording of meetings and lectures for archival purposes, and the transmission of voice data for voice over IP (VOIP) telephony, video conferencing and audio/video instant messaging. In these types of scenarios, recording is typically done using the local microphone for the particular computer being used. This recording configuration is highly vulnerable to environmental noise sources. In particular, this configuration is particularly vulnerable to a specific type of additive noise, that of a user simultaneously using a user input device, such as typing on the keyboard of the computer being used for sound capture, mouse clicks or even stylus taps, to name a few.
There are many reasons that a user may be using a keyboard or other input device during sound capture. For instance, while recording a meeting, the user may often take notes on the same computer. Similarly, when video conferencing, users often multi-task while talking to another party, by typing emails or notes, or by navigating and browsing the web for information. In these types of situations, the keyboard or other user input device may commonly be closer to the microphone than the speaker. Therefore, the speech signal can be significantly corrupted by the sound of the user's input activity, such as keystrokes.
Continuous typing on a keyboard, mouse clicks, or stylus taps, for instance, produce a sequence of noise-like impulses in the audio stream. The presence of this nonstationary, impulsive noise in the captured speech can be very unpleasant for the listener.
In the past, some attempts have been made to deal with impulsive noise related to keystrokes. However, these have typically included an attempt to explicitly model the keystroke noise. This presents significant problems, however, because keystroke noise (and other user input noise, for that matter) can be highly variable across different users and across different keyboard devices.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.